The invention relates to a device for low-warp hardening of thin-walled annular sealing members of hardenable metallic materials, having a C-shaped cross section, and capable of being charged in a tempering furnace or the like.
Sealing members of the kind referred to are employed when, in addition to the necessary elasticity, exacting requirements are imposed on heat stability and insensitivity to pressures. To obtain sealing members having such properties, they must be subjected to special heat treatment after forming. It has now been found that distortion will occur during heat treatment owing to the shape and thin-walled construction of the sealing members. This condition occurs, for example, during heat treatment in air circulation furnaces, protective gas furnaces, or salt baths, owing to uneven heating and the result is unusable parts.